Testing this axis is not as easy as it sounds. The mammalian body is a dynamic system with thousands of chemical reactions and interactions occurring simultaneously. Also, levels of cortisol are in a continual state of flux, depending on the time of day, the season, medications, diet, and stress levels. Underlying diseases like Urinary Tract Infections can affect these screening tests, and need to be controlled first. Because of all this variability, interpreting these tests can be problematic, and it is not uncommon to repeat them in the future to look for consistent findings and monitor trends.